The following discussion of the background to the invention is intended to facilitate an understanding of the invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or part of the common general knowledge as at the priority date of the application.
Current multi-impeller pumps have two or more identical impellers. Each of these impellers fits onto a respective separable keyed extension of the drive motor stub shaft. That is, each impeller after the first necessitates its own, further extension. Also, the current multi-impeller pumps have the halves of each impeller riveted or welded to each other, while a secondary fastener locates the impellers on or in relation to the extension shaft.
The present invention is directed to providing an alternative multi-impeller arrangement having at least two impellers.
While the arrangement of the present invention is very well suited to a multi-impeller arrangement having two impellers, it can be adapted for three or even more impellers. For ease of description, the invention largely is described with reference to an arrangement having two impellers.